الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Thirty-six low agricultural tunnels were constructed for controlling in environmental conditions surrounding plants to provide suitable climate and to maximize the agricultural productivity through winter season. Each treatment has two replicates with the same specifications.
The independent factors which used to evaluate the proposed tunnel performance were; tunnel covers thickness (40, 50 and 65 micron), number of cover sheets (single and double), soil surface cover type (bare soil, black plastic mulched and rice straw), solar intensity (w/m2.day), the ambient air temperature (oC), inner tunnel temperature (oC), inner tunnel relative humidity (%) and the soil surface temperature (oC). The tunnel performance was evaluated in respect of the Cucurbita productivity and the tunnel thermal efficiency. The proposed low tunnelswere studied by the thermal behavior inside the tunnel and thermal equilibrium under different circumstances.
The results of experiments indicated that, the air temperature inside all tunnels was higher than the ambient temperature during the period of the day-time. The double covering layer increased inner tunnel temperature and inner relative humidity by 6.4% and 3.2%, respectively compare with single covering layer under different cover thicknesses and different soil cover types. Covering soil surface with plastic mulch increased the soil surface temperature comparing with rice straw and bare soil by 2.5% and 3.5% respectively under different coverage thicknesses anddifferent number of covering layer